1. Technical Field
The present disclosure relates to a surface treatment method and a surface treatment device through which a processing gas is brought in contact with a heated processing object made of steel, and an element included in the processing gas is solid-solutionized to perform a surface treatment on the processing object.
2. Description of Related Art
When a processing object made of steel is subjected to a surface treatment, the processing object is heated, a processing gas is brought in contact with the processing object, and an element included in the processing gas is solid-solutionized in a surface of the processing object. As such a technique, for example, Japanese Patent Application Publication No. 2004-217958 (JP 2004-217958 A) proposes the following surface treatment method. In the surface treatment method, the processing object is heated through inductive heating, laser emission heating, or infrared radiation heating, a processing gas such as a nitriding treatment gas is brought in contact with a surface of the heated processing object, and thus a surface treatment is performed on the processing object.
In addition, Japanese Patent Application Publication No. 2014-118606 (JP 2014-118606 A) proposes the following surface treatment method. In the surface treatment method, first, a processing object is heated through high frequency inductive heating in a temperature raising unit. Next, the processing object is transferred to a carburizing treatment unit and under an atmosphere of a carburizing treatment gas, the atmosphere is heated, and thus a carburizing treatment is performed on the processing object. Next, the carburized processing object is transferred to a nitriding treatment unit, and the residual heat of the processing object in the carburizing treatment is used to bring ammonia gas in contact with the processing object to perform a nitriding treatment.